So your phone was charging fine yesterday, an update drops, and now the lock screen says 'Charging slowly' in that accusatory orange text. Welcome to the club. It's one of the most reported post-update complaints on Samsung, Pixel, and OnePlus devices, and 8 times out of 10 it has nothing to do with your battery dying.
Before you buy a new charger or panic-book a repair appointment, work through this in order. Stop as soon as charging speed comes back. Most people never make it past step two.
Quick sanity check: what 'Charging slowly' actually means
Android shows that message when the negotiated current is below roughly 1A at 5V — so under ~5 watts. Fast charging (Qualcomm QC, USB-PD PPS, Samsung Super Fast Charging, VOOC) all require the phone and charger to negotiate a voltage/current contract over the USB-C data lines. If that handshake fails, the phone falls back to dumb 5V charging and tells you so.
An update can break that handshake in three ways: USB configuration defaults get reset, the charging driver gets swapped for a buggy build, or a battery-protection feature gets switched on silently. All three are fixable. None require a new phone.
Step 1 — The 30-second fix (do this first)
Pull the cable out, flip the USB-C connector 180 degrees, and plug it back in. Yes, really. USB-C is reversible electrically, but the pins that carry the PD negotiation data aren't perfectly redundant on every cable. A dirty or slightly worn cable can pass data on one orientation and not the other.
While you're there, check the port. Shine a light in it. Pocket lint compresses into a felt pad at the bottom of the port and blocks the data pins. You don't need to charge the phone — you need the phone to talk to the charger, and lint kills that conversation. A wooden toothpick works. Never use metal.
Also confirm the charger isn't sitting behind a dead USB hub or a cheap extension lead. Rule that out in five seconds by plugging straight into the wall.
Step 2 — The 5-minute fix: reset the USB negotiation
If orientation and lint aren't the problem, the negotiation state is stuck. Android caches USB config per-session and updates sometimes leave it in a bad state.
- Unplug everything from the phone.
- To Settings → About phone and tap Build number seven times to unlock Developer options. Skip if you've already done this.
- Go to Settings → System → Developer options → Default USB configuration. Set it to No data transfer. This forces the phone to stop trying to enumerate as a USB device and lets it focus purely on the power contract.
- Reboot the phone (don't skip this — the USB stack only re-reads that setting on boot).
- Plug your original charger back in.
On Samsung firmware the equivalent path is Settings → Battery and device care → Battery → More battery settings. Look for Fast charging and Super fast charging toggles. Updates have a nasty habit of switching these off without asking. Same story on Pixel: Settings → Battery → Adaptive preferences.
Nine times out of ten, this is where the problem dies. The update reset a toggle or a USB profile, and you've just put it back.
Step 3 — The 15-minute fix: rule out the charging stack
Still slow? Now we start eliminating variables properly. Do these one at a time and re-test charging after each.
3a. Change one variable at a time
| Variable | What to try | Why it matters |
|---|---|---|
| Cable | Use the cable that came in the box, not the £3 Amazon one | Only e-marked USB-C cables carry the 5A the PPS spec needs. Non-e-marked cables max out at 3A and some fast-charge standards need more. |
| Charger brick | Try a known-good 25W+ PD charger from another device | If a different brick fast-charges, your original brick died or its firmware is incompatible post-update. |
| Wall outlet | Different socket entirely | Never trust a socket you haven't tested recently. |
Don't test all three at once. If you swap everything and it works, you learned nothing. Swap one, test, swap back, test.
3b. Check for an aggressive battery protection setting
Google and Samsung both rolled out adaptive charging that deliberately caps charge speed to protect battery health. On some builds the toggle is buried and defaults to ON after an update.
Path on Pixel 8 / Android 14:
Settings → Battery → Battery usage → Adaptive preferences
→ Turn off 'Adaptive charging'
→ Turn off 'Adaptive battery'Samsung One UI 6:
Settings → Battery and device care → Battery → More battery settings
→ Fast charging: ON
→ Super fast charging: ON
→ Protect battery (cap at 85%): OFFThat last one doesn't slow the charge rate, but it does make the phone look like it's charging slowly because it plateaus at 85% and sits there. Users report this constantly after a One UI update.
3c. Wipe the cache partition (not a factory reset)
If you're on a device with recovery mode (most Samsungs, some Motorolas), booting into recovery and clearing the cache partition dumps stale charging-driver caches without touching your data.
1. Power off completely.
2. Hold Volume Up + Power (Samsung: Vol Up + Bixby + Power).
3. Release when the Android logo appears.
4. Use volume keys to select 'Wipe cache partition'.
5. Confirm, then 'Reboot system now'.Pixels don't have a standalone cache wipe anymore — the equivalent is clearing cache per-app, which won't help here. Skip to 3d.
3d. Safe mode test
Boot into safe mode (hold Power, long-press the Power off option, tap the safe mode prompt). Charge the phone. If it fast-charges in safe mode, a third-party app — usually a battery saver, a VPN, or a sketchy 'battery doctor' app — is interfering with the charging service. Uninstall the recent additions one at a time.
Step 4 — If nothing works, this is the real fix
Two scenarios remain, and they're both real.
Scenario A: it's a genuine firmware bug in the update. This happens. The OnePlus 9 got a bad OxygenOS build in 2022 that broke 65W Warp Charge for weeks. Pixel devices have had similar post-feature-drop regression. The fix is to wait for the next security patch or roll back — and you can only roll back via a full flash, which wipes data. Check your device's subreddit and its XDA thread. If dozens of people on the same build have the same symptom, it's the firmware, not you.
Scenario B: the port or charging IC is physically failing. If cable, brick, USB config, cache, and safe mode all fail, and the phone also drops fast charging intermittently when you wiggle the cable, the USB-C port or the charge controller is on its way out. Updates don't cause this, but they often expose it because the new firmware is stricter about negotiating the fast-charge contract. Symptoms get worse when the phone is warm. That's a board-level repair — expect £60–£120 depending on model, or a warranty claim if you're inside two years.
What not to do
- Don't factory reset as a first move. It almost never fixes charging and you lose an hour restoring everything. Save it for after you've confirmed a firmware bug via community reports.
- Don't buy a 'fast charging booster' app. They do nothing but show ads.
- Don't use a charging cable thicker than the original. Fast charging is about the e-marker chip, not cable gauge.
- Don't charge overnight in a hot room to 'test' it. Heat throttles charging anyway and you'll read the wrong result.
Work the steps in order, test after each one, and don't change two things at once. That's it. The update didn't kill your phone — it reset a setting or broke a handshake, and you've got the tools to put it back.